While from functionality standpoint NVIDIA’s new graphics processing unit dubbed GeForce 7800 GTX has few differences compared to the GeForce 6800 architecture, the new chip features a number of enhancements beyond the previous family of products. One of such distinctions is ability of the processor to operate its different parts at different clock-speeds.
“As our chips become more advanced, we are implementing more complex clocking inside the chip. 430MHz is the primary clock speed of the chip and can be verified by fill rate tests. We can say that we have multiple clock domains, and that the reported core-clock frequency is based on the majority of the GPU's Logic. In the case of the GeForce 7800 GTX, this is 430 MHz,” NVIDIA’s spokesman Luciano Alibrandi told X-bit labs.
So far not much is known about different clock-speeds in particular, but it was discovered by various web-sites that the GeForce 7800 GTX’s pixel processors operate at 430MHz, Raster Operation (ROP) also functions at 430MHz, whereas certain other parts of the chip, presumably vertex processors, work at 470MHz.
Software used for tweaking NVIDIA GeForce graphics cards, such as RivaTuner suite, reports about 470MHz clock-speed of the latest graphics processor once a 3D application is enabled.
The peculiarity of the GeForce 7800 GTX will not affect overclockers, as the clock-speeds are applied proportionally, which means that once the primary speed of the graphics processor – 430MHz – is increased, other speeds also get higher.
“Using NVIDIA's Control Panel to overclock will also overclock other clocks within the chip proportionately,” Mr. Alibrandi informed.
NVIDIA GeForce 7800 GTX graphics chip features 24 pixel pipelines, 8 vertex pipelines and consists of more than 300 million transistors. By contrast, its top-end predecessor – GeForce 6800 Ultra – consisted of 220 million of transistors and had 16 pixel and 6 vertex processors. NVIDIA said its new graphics chip is aggressively more efficient than the previous-generation product, which was proved by X-bit labs’ measurements: by having more transistors and 30MHz higher clock-speed, the new chip consumes just 3W more than the former top-of-the-range product and delivers up to more than 50% performance improvement in graphics intensive games.